645214 has 4 divisors (see below), whose sum is σ = 967824. Its totient is φ = 322606.

The previous prime is 645187. The next prime is 645233. The reversal of 645214 is 412546.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 412546 = 2 ⋅206273.

It is a super-2 number, since 2×645214² = 832602211592, which contains 22 as substring.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is an unprimeable number.

645214 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 161302 + ... + 161305.

It is an arithmetic number, because the mean of its divisors is an integer number (241956).

2⁶⁴⁵²¹⁴ is an apocalyptic number.

645214 is a deficient number, since it is larger than the sum of its proper divisors (322610).

645214 is a wasteful number, since it uses less digits than its factorization.

645214 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 322609.

The product of its digits is 960, while the sum is 22.

The square root of 645214 is about 803.2521397419. The cubic root of 645214 is about 86.4107804050.

The spelling of 645214 in words is "six hundred forty-five thousand, two hundred fourteen".